A solid state imaging device having a back-illuminated type structure in which a lens is formed on the back side of a silicon layer with a light-receiving sensor portion being formed thereon. Insulating layers are buried into the silicon layer around an image pickup region, with the insulating layer being buried around a contact layer that connects an electrode layer of a pad portion and an interconnection layer of the surface side. A method of manufacturing such a solid-state imaging device is also provided.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of manufacturing a solid-state imaging device including a structure comprising at least a silicon layer in which a light-receiving sensor portion for effecting photoelectric-conversion is formed, an interconnection layer formed on the surface side of said silicon layer and in which a lens is formed on the rear side opposite to said surface side of said silicon layer, comprising: a process for forming a groove on said silicon layer around an image pickup region; a process for forming a groove on said silicon layer at a pad portion; a process for burying an insulating layer on said groove formed around said image pickup region; a process for burying an insulating layer on said groove formed at said pad portion; a process for forming a light-receiving sensor portion on said silicon layer after at least said insulating layer was formed around said image pickup region; a process for forming said interconnection layer on said surface side of said silicon layer; a process for connecting an electrode layer to said interconnection layer of said pad portion by burying a conductive material into said insulating layer buried into said groove of said pad portion; and a process for forming said lens on the back side of said silicon layer by using said insulating layer buried into said groove around said image pickup region as an alignment mark.
2. A method of manufacturing a solid-state imaging device according to claim 1 , wherein said silicon layer is etched by using a silicon nitride layer as a mask, a silicon oxide layer is buried into said groove as said insulating layer under the condition in which said silicon nitride layer is left, said silicon oxide layer is left only in said groove by removing said silicon oxide layer on the surface, said silicon oxide layer is protruded on the surface by removing said silicon nitride layer and said light-receiving sensor portion is formed on said silicon layer in said process for forming said groove on said silicon layer around said image pickup region.
3. A method of manufacturing a solid-state imaging device according to claim 1 , wherein a laminated substrate formed by laminating a silicon substrate, said silicon oxide film and said silicon layer is used, said grooves are formed around said image pickup region and at said pad portion with respect to said silicon layer of said laminated substrate and said interconnection layer is formed, whereafter said silicon substrate and said silicon oxide film are removed from said laminated substrate.
4. A method of manufacturing a solid-state imaging device according to claim 1 , wherein said process for forming a groove on said silicon layer around said image pickup region and said process for forming a groove on said silicon layer of said pad portion are executed at the same time and said process for burying an insulating layer into said groove formed around said image pickup region and said process for burying an insulating layer into said groove formed at said pad portion are executed at the same time.
5. A method of manufacturing a solid-state imaging device according to claim 1 , wherein said process for forming said groove on said silicon layer around said image pickup region and said process for burying said insulating layer into said groove formed around said image pickup region, said process for forming said groove on said silicon layer of said pad portion and said process for burying said insulating layer into said groove formed on said pad portion are executed separately.
6. A method of manufacturing a solid-state imaging device according to claim 5 , wherein said process for forming said light-receiving sensor portion on said silicon layer is executed after said insulating layer was buried into said groove formed around said image pickup region, whereafter a groove is formed on said silicon layer of said pad portion and an insulating layer is buried into said groove.
7. A method of manufacturing a solid-state imaging device according to claim 1 , wherein said process for decreasing the thickness of said silicon layer is executed by removing the rear side of said silicon layer after said process for forming said interconnection layer, whereafter a process for connecting said electrode layer to said interconnection layer by burying said conductive material into said groove.
8. A method of manufacturing a solid-state imaging device according to claim 7 , wherein said insulating layer buried into said groove around said image pickup region is used to detect an ending point required when the rear side of said silicon layer is removed.
9. A method of manufacturing a solid-state imaging device according to claim 1 , further comprising the steps of forming a second groove with a width narrower than that of said insulating layer and which reaches through said insulating layer to said interconnection layer of said pad layer on said insulating layer buried into said groove of said pad portion, forming a third groove with a width narrower than that of said insulating layer and whose is also wider than said second groove on an upper portion of said second groove and connecting said insulating layer to said interconnection layer of said pad portion by burying said conductive material into said second and third grooves.
10. A method of manufacturing a solid-state imaging device comprising a structure including at least a first silicon layer in which a light-receiving sensor portion for effecting photoelectric-conversion is formed, an interconnection layer formed on the surface side of said first silicon layer and in which a lens is formed on the back side opposite to said surface side of said first silicon layer, comprising: a process for forming a groove on said first silicon layer around an image pickup region; a process for forming a groove on said first silicon layer at a pad portion; a process for burying a second silicon layer made of amorphous silicon or polycrystalline silicon into said groove formed around said image pickup region; a process for burying a second silicon layer made of amorphous silicon or polycrystalline silicon into said groove formed at a pad portion; a process for forming a light-receiving sensor portion on said first silicon layer after said second silicon layer was buried around at least said image pickup region; a process for forming said interconnection layer on said surface side of said first silicon layer; a process for connecting an electrode layer to said interconnection layer by burying a conductive material through an insulating layer into said second silicon layer buried into said groove of said pad portion; and a process for forming said insulating layer over said first silicon layer, burying a metal layer on said insulating layer at its portion above said second silicon layer around said image pickup region and forming said lens on the back side of said first silicon layer by using said metal layer as an alignment mark.
11. A method of manufacturing a solid-state imaging device according to claim 10 , furthercomprising the steps of forming said groove on said first silicon layer of a laminated substrate around its image pickup region and at a pad portion by using said laminated substrate formed by laminating a silicon substrate, a silicon oxide film and said first silicon layer and removing said silicon substrate and said silicon oxide film from said laminated substrate after said interconnection layer was formed.
12. A method of manufacturing a solid-state imaging device according to claim 10 , wherein said process for forming said groove on said first silicon layer around said image pickup region and said process for forming said groove on said first silicon layer of said pad portion are executed at the same time and said process for burying said second silicon layer into said groove formed around said image pickup region and said process for burying said second silicon layer into said groove of said pad portion are executed at the same time.
13. A method of manufacturing a solid-state imaging device according to claim 1 , wherein said process for forming said groove on said first silicon layer around said image pickup region, said process for burying said second silicon layer into said groove formed around said image pickup region, said process for forming said groove on said first silicon layer of said pad portion and said process for burying said second silicon layer into said groove formed on said pad portion are executed separately.
14. A method of manufacturing a solid-state imaging device according to claim 13 , wherein the process for forming a light-receiving sensor portion on said first silicon layer is executed after said second silicon layer was buried into said groove formed around said image pickup region, whereafter a groove is formed on said first silicon layer of said pad portion and said second silicon layer is buried into said groove.
15. A method of manufacturing a solid-state imaging device according to claim 10 , wherein the process for decreasing the thickness of said first silicon layer by removing the rear side of said first silicon layer is executed after the process for forming said interconnection layer, whereafter the process for connecting the electrode layer to said interconnection layer by burying said conductive material.
16. A method of manufacturing a solid-state imaging device according to claim 15 , wherein said second silicon layer buried into said groove around said image pickup region is used to detect an ending point required when the back side of said first silicon layer is removed.
17. A method of manufacturing a solid-state imaging device according to claim 10 , wherein said first silicon layer is etched by using an insulating layer as a mask, said second silicon layer is buried into said groove in the state in which said insulating layer is left, said second silicon layer is left only in said groove by removing said silicon layer from the surface, said second silicon layer is protruded on the surface by removing said insulating layer and said light-receiving sensor portion is formed on said first silicon layer in the process for forming a groove on said first silicon layer around said image pickup region.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
November 3, 2004
September 5, 2006
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